Process of making o, o-dimethyl-o-(beta, beta-dichlorovinyl)-phosphate



.alkali metal carbonates,

soluble lower aliphatic alcohols.

- vinyl)-phosphate occurs United States Patent PROCESS OFMAKING, 0,0-DIMETHYL-O- (,B,,B-DICHLOROVINYL)-PHOSPHATE Walter Lorenz, Wuppertal-Elberfeld,

to Farbenfabriken B sen, Germany,

Germany, assignor ayer Aktiengesellsehaft, Levera corporation of Germany No Drawing. Application September 15, 1954 Serial No. 456,332

application Germany May 25, 1954 8 Claims. (Cl. 260461) Claims priority,

ing products of substantially and in obtaining these in high yield.

A principal object of the present invention is the pro- A further a new improvement in the .manufacture of 0,0-dimethyl-O-(fl,/3-dichlorovinyl) -phosphate.

In accordance with the invention it has been found that the hitherto unknown 0,0-dimethyl-O-(;8,B-dichlorovinyl)- phosphate can be obtained by contacting (5,5,,8-trichloroa-hydroxyethyl)-dimethyl-phosphonate with alkaline reacting substances, e. g. with alkali metal hydroxides, ammonia or organic amides. carried out in water or water The reaction temperature may be within the range of l00 C. but temperatures of 20 to about 70 C. are preferred.

The rearrangement of Preferably the reaction is with alkali metal hydroxides to form ketones or aldehydes and the corresponding dialkylphosphites. The rearrangethe solution has reached the neutral point.

2,865,943 Patented;.Dec. 23, :1 958 ment, however, is limited to this methyl ester and cannot be applied to higher alkyl homologs. Not even the diethyl phosphonate is capable of rearranging to thecorresponding diethyl dichloro vinyl phosphate.

The rearrangement is shown bythefollowing equation:

mls. of concentrated ammonia solution are added. After heating for half anhour to '5060 C. the .pH-value of over at 0.1 mm. at 6971 C. in an amount of 53 g- 48% of the theoretical).

Example 2 129 g. of (p,[3,5-trichloro-a-hydroxyethyl)-dimethylphosphonate are dissolved in 250 ccm. of methanol. To This solution is added a solution of sodium methylate, prepared from 11.5 g. of metallic sodium in 100 ccm. of methanol, at a temperature below 3 C. The sodium chloride is filtered off with suction and the methanol is distilled off in vacuo. The oily residue is taken up in benzene and Washed with water until the washing .solution is free of ionic chlorine. After drying over sodium sulfate the benzene is distilled oil, the residue is fractionated at 3 mm. 45 g. of 0,0-.dimethyl-O-(tie-dichlorovinyl)-phosphate distilled over at 86-87 C. (49% of the theoretical).

Example 3 129 g. of (,8,e,p-trichloro-whydroxyethyl)-dimethylpliosphonate are dissolved in 250 ccm. of water. At a temperature of 2530 C. there are added dropwise 53 g. of triethylamine. After stirring for half an hour the oil is taken up in tetrachloromethane. After drying and distilling oif the solvent, 65 g. of [3,[3-dichlorovinyldimethylphosphate are obtained (51% of the theoretical).

Example 4 129 g. of (,8,,6,fl-trichloro-a-hydroxyethyl)-dimethylphosphonate are dissolved in 500 ccm. of water and warmed up to 3070 C. While stirring there is added dropwise a solution of 20 g. sodium hydroxide in 50 ccm. of water. The reaction is exothermic and heavy colorless oil separates. The temperature rises to about 90 C. The vinyl ester is recovered as described in the foregoing examples. 64 g. of 0,0-dimethyl-O-(,B,fl-dichlorovinyl)-phosphate are obtained (58% of the theoretical).

Example 5 129 g. of ([9,5,5-trichloro-ol-hydroxyethyl)-dimethy1- phosphonate are dissolved in 500 ccm. of Water as described in the foregoing examples. A concentrated solution of 20 g. sodium hydroxide is added dropwise at a temperature of 5l0 C. After recovering as described in the foregoing examples there are obtained 60 g. of 0,0-dimethyl-O-(@edichlorovinyl)phosphate 56% of the theoretical).

Example 6 g. of (5,5,5 trichlo-ro cc hydroxyethyl)dimethylphosphonate are dissolved in 500 ccm. of water at a temperature of C. At this temperature are added dropwise 30 g. of sodium carbonate in 200 ccm. of water and the solution is stirred for a further half hour at 70 75 C. After this period the solution becomes neutral. The heavy oil is taken up in tetrachloromethane and recovered as described in the foregoing examples. There are obtained 58 g. of 0,0-dimethyl-O-(fifi-dichlorovinyl)- phosphate which distills over at 1 mm. at 69-71" C. (53% of the theoretical).

The 0,0 dimethyl O (5,;8-dichlorovinyl)-phosphate may be employed in controlling many types of insects and mites such as, for example, the black bean aphid, green peach aphid, pea aphid, chrysanthemum aphid, greenhouse thrips, California red scale, citrus red spider, greenhouse red spider, milkweed bug, mealy bug, sow bug, German cockroach, southern army worm, yellow fever mosquito, malarial mosquito, Mexican bean beetle, T ri bolium confusum, and black carpet beetle.

Thenew compound may also be used in combination with insecticides such as lead arsenate, nicotine, rotenone, pyrethrum, benzene hexachloride, l,l,l-trichloro 2,2 di(p-chlorophenyl)-ethane, dodecyl thiocyanate, phenothiozinc, and the like; with fungicides such as sulfur, various copper compounds, mercury salts, and the like; and with various types of plant foods and fertilizers.

While the invention has been described with particular reference to specific embodiments, it is to be understood that it is not to be limited thereto, but is to be construed broadly and restricted solely by the scope of the appended claims.

The vary good insecticidal properties are shown by the fact that aphids and spider mites are for instance completely killed in a concentration of 0.01 percent. Furthermore the 0,0-dimethyl-O-(fifi-dichlorovinyl)phosphate is distinguished by a remarkable systemic action.

We claim:

1. Process for the production of the 0,0-dimethyl-O- (p,fi-dichlorovinyl)- hosphate which comprises contacting (13,13,B-trichloro-a-hydroxyethyl) dimethyl phosphonate with an alkaline reacting agent.

2. Process for the production of 0,0-dimethy1-O-(fl,pdichlorovinyl)-phosphate which comprises contacting a solution of (6,6,6-trichloro a hydroxyethyl) dimethylphosphonate with a solution of a member selected from the group consisting of alkali metal hydroxides, alkali metal carbonates and ammonia and recovering the 0,0- dimethyl-O-(5,;3-dichlorovinyl)-phosphate.

3. Process for the production of 0,0-dimethyl-O-(fi,fidichlorovinyl)-phosphate which comprises contacting a solution of (,8,;8,;8 trichloro a hydroxethyl) dimethylphosphonate with a solution of a member selected from the group consisting of alkali metal hydroxides, alkali metal carbonates and ammonia in a solvent selected from the group consisting of water and lower aliphatic alcohols at a temperature from about 0-100" C. and recovering the 0,0-dimethyl-O-([3,;8-dichlorovinyl)phosphate.

4. Process in accordance with claim 3 in which the alkaline reacting substance is sodium hydroxide.

5. Process in accordance with claim 3 in which the alkaline reacting substance is sodium carbonate.

6. Process in accordance with claim 3 in which the alkaline reacting substance is ammonia.

7. Process in accordance with claim 3 in which the solvent is water.

8. Process in accordance with claim 3 in which the solvent is methanol.

References Cited in the file of this patent UNITED STATES PATENTS Ladd et al Oct. 7, 1952 Ladd et al. Mar. 10, 1953 OTHER REFERENCES 

1. PROCESS FOR THE PRODUCTION OF THE O,O-DIMETHYL-O(B,B-DICHLOROVINYL)-PHOSPHATE WHICH COMPRISES CONTACTING (B,B,B-TRICHLORO-A-HYDROXYETHYL)-DIMETHYL-PHOSPHONATE WITH AN ALKALINE REACTING AGENT. 